import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Text Field Border demo',
      home: HomeScreen(),
    );
  }
}

class HomeScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Material(
      child: Center(
        child: Padding(
          padding: const EdgeInsets.all(8.0),
          child: TextField(
            decoration: InputDecoration(
              border: OutlineInputBorder(
                borderSide: BorderSide(color: Colors.pink),
              ),
            ),
          ),
        ),
      ),
    );
  }
}